Low-water alarm.



C. W. FORD.y

LOW WATER ALARM. APPLICATION FILED JUNI: 19, 1912.

Patented June 10, 1913 [l1/venian' orrweg.

CLARENCE W'. FGRD, 0F-PTTSBU'RGH, PENNSYLVANIA.

LOWWVATER ALARM.

Application ined June is; i912.

To all whom it' may concern:

Be it known that LCLARENCE W. Fono, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain'new and useful Improvements in Low- Water Alarms, of-which the following is a specification.

My invention relates to low water alarms, that 1s tosay, to devices totl signaling or in Y dicating when the water in steam boilers falls below the predetermined level, and it relates more specifically to apparatus for Vestablishing or completing an electric cirapparatus is connected to the shell or other suitable part of the boiler.r

The nature and characteristic features 4of my invention will be more readily under-'- stood from the following description, taken in connection with the accompanying drawings forming partl'sereof, in which- Figure l is a view, partly in section and partly in elevation, of an apparatus' embodying the main features of my present invention, `the electric circuit being shown diagrammatically in connection therewith; and Fig. 2 is a view similar to' Fig. 1, the section being taken transversely thereto, and certain of the interior parts being also shown in section.

Referring to' the drawings, in the particular embodiment of my invention therein shown, 3 is the shell of the boiler into which is threaded a horizontal pipe t at a location corresponding to that of the lowest desirable level of the water contained within the boiler.

5 is an elbow or other suitable pipe lit- Iting which .supports and establishes comf munication with a vertical expansion tube 6 which is preferably made of brass or other suitable material having a higher coefficient Specilcation of Letters Patent.

llatentetl June 10, 1913. Serial No, 764,487.

of expansion than other parts of the structure. At the top end of the tube 6 is an enlarged portion. I forming a chamber which insures the eticient operation ofthe apparatus as will hereinafter be more fullv set forth. y u

Threadedl on the lower end of the pipe 6 above the elbow 5 is a nut 8 which serves ameans o support and adjustment for a pipe 9 whichl surrounds the pipe 6 and its enlarged portion 7.' The pipe 9, preferably made of iron or other suitable material having a lower coefficient of expansion than the tube 6, constitutes a housing for the protec tion of the working parts of the apparatus and also acts as a support for certain ofthe essential elements. The pipe 9 is provided at its lower end with a disk-like portion 10 which rests 'upon the nut 48, and after the final adjustment of the apparatus is obtained the disk 10, nut 8, and pipe 6 are all prefer'- ably brazed together to form a practically integral structure whichwill maintain the proper adjustment of the working parts and prevent unskilled persons. from tampering with the apparatus.

Secured by brazing or in any other suitable manncrto the tube 6, at. itsupper end immediately below the enlarged portion 7, is an encircling portion 11 of a spring steel tlngerlZ which extends downwardly alongside of the ypipe 6. The finger 12 has an offset. portion ladjacent the end which is secured to tube Gl which odset portion 13 forms a shoulder' against which a pin le bears; The pin 14 is rigidly secured iin thel outer surrounding pipe 9 and is practicallyv 'aunitary portion of the supporting housing. The lower end of the pipe or housing 9 also supports a stationary contact spring 15 which is secured thereto by means of a screw 16 which is electrically insulated from the housing 9 by means of a bushing 17 made of any suitable insulating material. The contact spring 15 is arranged adjacent the lower end of the depending spring .12 but is normally out of contactfwith the same.

' The screw 16 'which supports the stationary l Contact spring 15 Ais provided with a nutA 18 for. the purpose of ysecuring an electric wire 19 thereto,.which wire 19 forms part of the electric circult- .and isconnected with an alarm bell 20 from whence extends a wire 21 which is connected to abattery 2Q or other suitable source of electrical energy, the batteryl bemg also electrically connected by means of a wire 23 to any suitable part ot the apparatus, the same being shown tor yconvenience connected to the elbow 5.

The operation or" the^apparatus is as follows :wtio long as the 'water in the boiler is maintained above the level ot' the connection of the horizontal pipe t, the vertical expansion tube (i and its enlarged portion or chambeif? wilibe maintained iull of water, and onaccount of being arranged out side of' theboiler, the temperature of the water contained therein will fall below that ot' the water within the boiler, and the parts will be maintained in the position substantially as shown in Fig. l of the drawings. l/Vhen, however, the water falls below the level of the connecting pipe e, the water within thetube 6 and its enlarged portion 7 will be drained back into-the boiler and steam will enter the tube 6 and the higher temperature of the steam will cause the tube to expand, carrying with it the spring 12 and causing the shoulder-13 tobear harder against the projecting pin 14 which is car Vried by the outer tube or housing 9. The

pressure which :is thus exerted against the 4shoulder 13 will cause the lower end of the the electric circuit will thereby be closed and the alarm bell 2O will hesounded. The purpose of the enlarged portion 7 at the u per ond of t-ube 6 is to form a chamber 1wiich not onlypresents a greater surface 'tor the condensation of the steam which might otherwise remain in the tubev 6 and prevent the water from entering the same, but also has been found in practice to cause the apparatus to act more eiliciently and positively than when said enlarged portion is omitted.

Having thus described the nature and characteristic features of my invention what claim as new and desire to secure by Letters Patent is A 1. In a device of the character described, in combination with a boiler, an expansion tube in communication therewith, a contact element carried by said expansion tube comprising an elongated finger iixedly secured at one end to said expansion tube, a shoulder on said finger adjacent the fixed end thereof, a housing, a projection'carried by said housing engaging said shoulder, and a stationary Contact member supported adjacent the free end of said finger.

2. ln a device of the character described, in combination with a boiler, an expansion tube 1n communication therewith, a contact member lixedly secured at one end to said.

Locales the finger, and a stationary contact member supported by the housing adjacent the free end of said finger.v

3. ln a device of the character described,

tube in communication therewith, means controlled by said tube for establishing an electric circuit, and an enlarged portion constituting a chamber 'at the end of said tube.

in combination with a boiler, an expansion tube in communication therewith, an enlarged portion constituting a chamber at the end of said tube, a Contact element ixedl'y. secured at one end to said expansion tube and comprising an elongated linger, a stationaryl contact member supported 'adjacent the free end of said 'contact linger, and means for deilecting said finger when said tube is expanded.

in combination `with a boiler, an expansion tube in communication with 'the boiler, ani, enlarged portieri constituting a chamber at`Y the end of said tube, a contact element fixedly secured at one end to said expansion tube and comprising an elongated nger, al stationary contact member supported adjacent the free end' ot said contact finger, and means ior detiecting said finger when said tube is expanded comprising a shoulder on said finger adjacent the fixed end thereof, a housing, and a projection carried by said housing engaging said shoulder. P (3. In a device of the character described, in combination with a boiler, an expansion `tube in communication therewith, an en-- larged portion constituting a :chamber at the end of said tube, a contact member ixedly secured lat one end to said expansion tube and comprising an elongated-linger having an offset portion forming a shoulder adjacent the fixed end of said inger, a hcusing,a projection carried by said housing engaging the offset portion of the nger, and a stationary contact member adjacent the free end of said nger. v

7. ln a device of the character described, in conibinationwith a boiler, an expansion tube'in communication therewith, an enlarged portion constituting a chamber at the end of said tube, a contact member tube adjacent the enlarged end thereof andcomprising an elongated linger extending along the side of said tube and having an offset portion forming a shoulder adjacentithe fixed endl of said finger, a housing, a projection carried byl said housing engaging the offset portion of the finger, and a stationary Contact member adjacent the free end of said finger.

8'. In a device of thecharacter described, in combination with avboilcr, an expansion Atube in'comniunication therewith, an' cn-` 85 5. ln a device of the character described, I

in combination with a boiler, an expansion 4t. ln a device of the character-described, 75

ixedly secured at one ond to said expansion .secured at one end iifngefl pei-tion crmstutng a chamber at Une und of said. tube, ujconmct member fxdly to said expansion tube und comprising an dung-ated ngcr having un @Vs-et portion fol-ming n, shoulder ndjm een@ Live .Grind and of said fingenl pipe forming a proteoive hnusiug aum-minding said expansion tube, :L pin mounted in Sad homing engaging the. @Haat pm'tn of the 1U Enger, and a stntmlary cos'tuct member suppm-edby the housing ajacexl the free 1 und of said finger.

in cstxmuny wheref,

signed my name 1n the presence of messes.

two WML- CLARNGE V1" FUD.

Nimesses {Ema/'Mm E. KIRK, Lows WEBER.

' have hmmm@ 

